Build Android Business App

I’m building a dedicated Android business application and need it taken from concept to a production-ready release. Two capabilities are non-negotiable: secure user authentication—limited to classic email + password sign-in—and a smooth, reliable payment-processing flow... (Budget: ₹600 - ₹19600 INR, Jobs: Android, Android App Development, Android SDK, Java, Kotlin, Mobile App Development, Payment Processing, PHP)